Accompanying the recent spread of personal computers in households, digital still cameras capable of inputting image data such as photographed scenes and portraits into personal computers are rapidly becoming available. In addition, many cellular telephones, smart phones, and tablet type terminals are being equipped with camera modules for inputting images. The number of pixels in imaging elements such as CCD's and CMOS's is increasing in devices having such photography functions, and there is demand for high resolution and high performance of imaging lenses. Performance corresponding to 5 megapixels or greater, and more preferably 8 megapixels or greater, is desired.
In response to such demands, imaging lenses having a five lens configuration, which is a comparatively large number of lenses, have been proposed. Further, imaging lenses having a six lens configuration, which is an even greater number of lenses, have been proposed to further improve performance. For example, Japanese Unexamined Patent Publication Nos. 2004-294910, 2005-258294, and 4 (1992)-317020 disclose imaging lenses having six lens configurations, including a first lens having a negative refractive power, a second lens, a third lens, a fourth lens, a fifth lens having a positive refractive power, and a sixth lens having a negative refractive power, provided in this order from an object side.